Blow torch to bell and body?

[tubatodd]

I was watching a Japanese video of Tubassadors where they were looking at the Yamaga 623. I don't know the language and didn't both to translate the text that was there. But at one point in the video the horn is disassembled to be cleaned and "tweaked" in some way. At the time stamp below you see they take a torch to the bell, slides and leadpipe. It doesn't look like enough constant heat to loosen solder.

Edit: I had Google lens help translate the text on the screen and it appears the heat is for helping with possible misalignments. I can understand that with the slides and braces, but the bell is confusing to me.

What are they doing?

@bloke



Thank you in advance.

[bloke]

I can watch more of it later, but at first glance it looks like some annealing hocus-pocus. If they didn't heat the bell enough to melt the silver or burn the lacquer, they didn't anneal it.

The purpose of annealing bells is to make them easier to stretch and shape on a big bell mandrel on a lathe without cracking... or aftermarket to soften up an area of an instrument enough to make it easier to remove some stubborn dent.

If I didn't watch enough of the video for my comments to make sense, I will edit them later. I watched about 8 seconds, and a customer from an hour and a half away with some sort of trombone distress just drove up.

[MiBrassFS]

Here he’s holding a small part and waiving the torch at his hand.

Things that make you go, “Hmmm…”

It would be interesting to know “more” about all of this.

[the elephant]

This is an example of the Dunning-Kruger Effect. This isn't doing anything. Nothing. Nothing at all. Zero effect.

He either honestly believes this nonsense or he is overtly lying to the customer. Either way, whether intentionally or not, he is ripping them off.

[MiBrassFS]

“Plain speak” from @the elephant.

I can’t disagree at all…

[gocsick]

We can put some numbers to things....

So the annealing point of brass is between 370-420C ( approx 700-800F).. These are ASTM Handbook values for yellow/gold brass. Below that you are not going to remove any work hardening. The general rule of thumb for heat treatment of non-ferrous metals is you want to be above 1/2 the melting temperature for annealing to occur in a reasonable amount of time. So for practical annealing in a minute or so... you need to be HOTTER than the handbook annealing point. Brass melts at 950ish C (depending on the specific alloy)... For practical annealing you want to be around 475 C or hotter.

60/40 solder flows at 190C (375F)

The lacquer burns at around 150C.

Silver plating has a melting point of of about 960C...right around the same as brass. So that would survive annealing the bell just fine.

Edit @UncleBeer corrected the above. I spent some time looking it up.. Yes flame annealing will destroy silver plate. My brain was 100% stuck on controlled atmosphere industrial oven heating.. where pesky things like oxygen and combustion products don't wreak havoc on my beautiful theoretical chemistry.

[UncleBeer]

Silver plating has a melting point of of about 960C...right around the same as brass. So that would survive annealing the bell just fine.

You can absolutely burn (damage) silver plate with much less heat than the annealing temp.

[bloke]

I just don't run into many work-hardened tuba bells...particularly not B&S-made ones...

(I ran into a really-REALLY old 20" King bell that had one area (a few years ago)...This was for someone's franken-build...but I was able to "work around" that without putting a torch to that area. (Yeah...per "Unc's comments...it was silver, the silver was in pretty good shape, and I didn't want to screw up the looks.)

Rudy Meinl bells are "weird" (sorta "most of them seem work-hardened without ever being - well - worked), but I still manage to straighten them out without heating them up.

If anyone remembers the 5/4 RM C that I owned for two or three years (and tricked out a bit), its bell had some significant creases, etc...but - by the time I sold it (to a friend) there really wasn't much of a trace of any of them...and the original lacquer was quite intact. Something else sort of weird about the seem-to-be-pre-work-hardened-RM bells: When they crease (and I manage to repair them), the creases often don't leave any crease lines...This has nothing to do with bloke-prowess...It's something odd re: those bells.

I've learned to not publicly state whether-or-not I believe someone is engaging in any particular type of quackery, so...

...also: My tubas bells heat up more than than, simply when executing a regular ff , so - as far as I'm concerned - those guys (having to resort to artificial heat) are nothing but a couple of pansies.

bloke "The amount if heating I saw was little more than I use to quick-dry wet lacquer before it runs or collects dust...and DO NOT TRY WHAT I ROUTINELY DO AT HOME...You'll burn your freakin' house down."

[tubatodd]

So what I am reading is that this method of horn repair/maintenance/tweaks is....

[tubatodd]

Here he’s holding a small part and waiving the torch at his hand.

...

Best way to dry your hands?

[MiBrassFS]

Here he’s holding a small part and waiving the torch at his hand.

...

Best way to dry your hands?

Definitely one way!

[bloke]

I trumpet player friend of mine made a video of me re-soldering (torch) one of those plastic trumpets (yeah...like a pBone or CoolWinds tuba) back together...Yes, I actually had a flame going. Of course, I actually did nothing, but - had that thing actually been broken and also not repairable - it would have been pretty funny to make a video of melting it into a pool of plastic.

[greenbean]

Maybe this guy is a germophobe. He is merely sanitizing the tuba before he begins to work on it!!